Furo (2,3d) pyrimidines

ABSTRACT

Compounds of the formula ##STR1## wherein R is alkyl of 1-4 carbon atoms, phenyl, or phenyl substituted by one or more halogen or trifluoromethyl, and Z is ##STR2## wherein R 1  is hydrogen, alkyl of 1-4C, 2,2-dimethyldioxolan-4-yl methyl, or 2,3-dihydroxy prop-1-yl, R 2  is ##STR3## wherein ##STR4## is morpholino, pyrrolidino, piperidino or hexamethyleneimino, and n is an integer from 4 to 7. The compounds are prepared by reacting R-substituted 4-chloro-2-methyl furo (2,3d) pyrimidine with HZ. The compounds possess antiulcerous, antibronchoconstrictive and anticholinergic, analgesic, antihistamine, diuretic, cardiovascular analeptic, antiinflammatory and hypertensive properties.

The present invention relates to novel furo (2,3d) pyrimidines, their process of preparation and their therapeutic application.

The compounds according to the invention correspond to the general formula: ##STR5## in which: -R represents an alkyl radical containing up to 4 carbon atoms or a phenyl ring optionally substituted by one or more halogen atoms, or by a trifluoromethyl radical; and

-Z represents one of the following: ##STR6## in which:

R₁ represents a hydrogen atom, an alkyl radical containing up to 4 carbon atoms, a 2,2-dimethyl dioxolan-4-yl methyl radical or a 2,3-dihydroxy prop-1-yl radical,

R₂ represents:

- a β-amino ethoxy group of formula ##STR7## - a carboxamide group of formula ##STR8## or a group of formula ##STR9## the symbol ##STR10## representing a morpholino, pyrrolidino, piperidino or a hexamethyleneimino radical, and

n is an integer of between 4 and 7.

The process according to the invention consists in condensing a 4-chloro-2-methyl furo (2,3d) pyrimidine of formula: ##STR11## in which R represents an alkyl radical containing up to 4 carbon atoms or a phenyl ring optionally substituted by one or more halogen atoms, or by a trifluoromethyl radical, with an amine derivative of formula III

    hz'                                                        (iii)

in which Z' represents one of the following: ##STR12## in which:

R₁ ' represents a hydrogen atom, an alkyl radical containing up to 4 carbon atoms,

R₂ represents

- a β-amino ethoxy group of formula ##STR13## - a carboxamide group of formula ##STR14## - or a group of formula ##STR15## the symbol ##STR16## respresenting a merpholino, pyrrolidino, piperidino or a hexamethyleneimino radical, and n is an integer of between 4 and 7. to produce a derivative corresponding to the formula: ##STR17## and, optionally subjecting a derivative of the formula I' in which Z' represents a 2-methoxycarbonyl anilino radical, to a transesterification in the presence of sodium with 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane, to give the derivate of formula: ##STR18## which may be then transformed into a derivative of formula: ##STR19## by opening of the dioxolane cycle with hydrochloric acid.

It is to be noted that the condensation of the 4-chloro-2-methyl furo (2,3d) pyrimidines of formula (II) with the amine derivatives of formula (III) is conducted:

in benzene under reflux when Z' represents a ##STR20## radical, in which n is an integer of between 4 and 7, and

in acetic acid, in the presence of catalytic quantities of concentrated hydrochloric acid, when Z' represents a radical ##STR21##

The following preparations are given, by way of example, to illustrate the invention.

EXAMPLE 1:

2-methyl-4-pyrrolidino-6-(metatrifluoromethyl phenyl) furo (2,3d) pyrimidine. (Code No. 72497)

14.2g (0.2 mol) of pyrrolidine was added, drop by drop, to a solution of 31.3g (0.1 mol) of 2-methyl-4-chloro-6-(metatrifluoromethyl phenyl) furo (2,3d) pyrimidine in 350 c.c. of benzene heated at 60° C, and the mixture was then refluxed for 6 hours. The mixture is filtered whilst warm, the filtrate is evaporated under vacuum, and the residue is recrystallised from methylethyl ketone.

Melting point = 203° C

Yield = 58%

Empirical formula = C₁₈ H₁₆ F₃ N₃ O

Elementary analysis:

    ______________________________________                                                    C        H         N                                                ______________________________________                                         Calculated (%)                                                                              62.24      4.64      12.10                                        Found (%)    62.13      4.69      12.03                                        ______________________________________                                    

EXAMPLE 2:

N-(2,6-dimethyl furo(2,3d) pyrimidin-4-yl) methyl anthranilate (Code No. 7280)

A suspension of 4.55 g. (0.03 mol) of methyl anthranilate, 5.45 g. (0.03 mol) of 2,6-dimethyl-4-chloro furo (2,3d) pyrimidine and 0.1 c.c. of concentrated hydrochloric acid in 30 c.c. of acetic acid were heated at 80° to 90° C for 30 minutes. The precipitate formed is filtered, placed in suspension with 50 c.c. of ethanol, alkalinised with concentrated ammonia, diluted with 200 c.c. of water, filtered, washed with water, recrystallised from ethanol and then from acetone.

Melting point = 186° C

Yield = 34%

Empirical formula = C₁₆ H₁₅ N₃ O₃

Elementary analysis:

    ______________________________________                                                    C        H         N                                                ______________________________________                                         Calculated (%)                                                                              64.63      5.09      14.14                                        Found (%)    64.75      5.26      14.14                                        ______________________________________                                    

EXAMPLE 3:

N-(2,6-dimethyl furo(2,3d)pyrimidin-4-yl)- 4'-methyl-2',2'-dimethyl-1',3'-dioxolane anthranilate. (Code No. 730 367)

0.3 g of sodium is dissolved, with warming, in 260 c.c. of 2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane. After cooling, 65.5 g (0.22 mol) of N-(2,6-dimethyl furo(2,3d) pyrimidin-4-yl) methyl anthranilate of code No. 7280 obtained as indicated in the preceding example, is added thereto and the resultant mixture is heated for 5 hours at 140°-150° C, the methanol formed being distilled off under nitrogen. The mixture is diluted with 2l of water, filtered, washed with water and recrystallized from ethanol.

Melting point = 160° C

Yield = 50%

Empirical formula = C₂₁ H₂₃ N₃ O₅

Elementary analysis:

    ______________________________________                                                    C        H         N                                                ______________________________________                                         Calculated (%)                                                                              63.46      5.93      10.57                                        Found (%)    63.42      5.95      10.37                                        ______________________________________                                    

EXAMPLE 4:

4-(β,γ-2'-dihydroxypropoxycarbonyl-phen-1'yl amino)-2,6-dimethyl furo (2,3d) pyrimidine. (Code No. 730 387).

A suspension of 58g (0.147 mol) of N-(2,6-dimethyl furo (2,3d) pyrimidin-4-yl)-4'-methyl-2',2'-dimethyl-1',3'-dioxolane anthranilate of Code No. 730 367 obtained as indicated in example 3, in 500 c.c. of 2N hydrochloric acid is heated for 45 minutes under reflux. The mixture is filtered whilst warm, neutralized with 100 c.c. of triethylamine, the precipitate formed is filtered, washed with water and recrystallised from ethanol.

Melting point = 179° C

Yield = 30%

Empirical formula = C₁₈ H₁₉ N₃ O₅

Elementary analysis:

    ______________________________________                                                    C        H         N                                                ______________________________________                                         Calculated (%)                                                                              60.49      5.36      11.70                                        Found (%)    60.62      5.36      11.71                                        ______________________________________                                    

The compounds listed in the following Table I have been prepared according to the same mode of operation.

                                      TABLE I                                      __________________________________________________________________________      ##STR22##                                                                                                              Mel-                                                                       Mole-                                                                              ting                                  Code                          Empirical                                                                             cular                                                                              Point                                                                             Yield                                                                             Elementary Analysis             No.  R      Z                 Formula                                                                               Wt. (° C)                                                                      %      C   H  N                    __________________________________________________________________________     72 498                                                                              ##STR23##                                                                             ##STR24##         C.sub.19 H.sub.18 F.sub.3 N.sub.3 O                                                   361.36                                                                             129                                                                               29 Calcu- lated (%) Found                                                             63.15                                                                              5.02 5.06                                                                         11.63 11.55          72 557                                                                              "                                                                                     ##STR25##         C.sub.18 H.sub.16 F.sub.3 N.sub.3 O.sub.2                                             363.33                                                                             178                                                                               42 Calcu- lated (%)  Found                                                        (%) 59.50 59.36                                                                        4.44 4.49                                                                         11.57 11.67          72 535                                                                              "                                                                                     ##STR26##         C.sub.20 H.sub.20 F.sub.3 N.sub.3 O                                                   375.38                                                                             126                                                                               53 Calcu- lated (%) Found                                                             63.99 63.77                                                                        5.37 5.45                                                                         11.19 11.02          72 561                                                                              "                                                                                     ##STR27##         C.sub.21 H.sub.22 F.sub.3 N.sub.3 O                                                   389.41                                                                             145                                                                               45 Calcu- lated (%) Found                                                             64.77 64.74                                                                        5.69 5.77                                                                         10.79 10.85          71 384                                                                              ##STR28##                                                                             ##STR29##         C.sub.17 H.sub.16 ClN.sub.3 O                                                         313.78                                                                             186                                                                               43 Calcu- lated (%) Found                                                             65.07 64.89                                                                        5.14 5.15                                                                         13.39 13.22          72 544                                                                              ##STR30##                                                                             ##STR31##         C.sub.18 H.sub.18 Cl N.sub.3 O                                                        327.81                                                                             187                                                                               39 Calcu- lated (%) Found                                                             65.95 65.74                                                                        5.53  5.45                                                                        12.82 12.60          72 545                                                                              "                                                                                     ##STR32##         C.sub.17 H.sub.16 Cl N.sub.3 O.sub.2                                                  329.78                                                                             226                                                                               29 Calcu- lated (%) Found                                                             61.91 62.01                                                                        4.89 4.87                                                                         12.74 12.56          72 700                                                                              "                                                                                     ##STR33##         C.sub.19 H.sub.20 Cl N.sub.3 O                                                        341.83                                                                             147                                                                               32 Calcu- lated (%) Found                                                             66.76 66.59                                                                        5.90 5.76                                                                         12.29 12.14          72 682                                                                              "                                                                                     ##STR34##         C.sub.20 H.sub.22 Cl N.sub.3 O                                                        355.86                                                                             126                                                                               24 Calcu- lated (%) Found                                                             67.50 67.48                                                                        6.28 6.26                                                                         11.81 11.96          730372                                                                             CH.sub.3                                                                               ##STR35##         C.sub.15 H.sub.13 N.sub.3 O.sub.3                                                     283.28                                                                             260                                                                               39 Calcu- lated (%) Found                                                             63.59 63.50                                                                        4.63 4.82                                                                         14.88 15.03          740119                                                                             CH.sub.3                                                                               ##STR36##         C.sub.21 H.sub.24 N.sub.4 O.sub.4                                                     396.43                                                                             152                                                                               55 Calcu- lated (%) Found                                                             63.62 63.83                                                                        6.10 6.30                                                                         14.13 14.16          730525                                                                             CH.sub.3                                                                               ##STR37##         C.sub.19 H.sub.20 N.sub.4 O.sub.2 +1/2                                         H.sub.2 O                                                                             345.39                                                                             225                                                                               20 Calcu- lated (%) Found                                                             66.07 66.29                                                                        6.29 6.25                                                                         16.22 16.04          730508                                                                             CH.sub.3                                                                               ##STR38##         C.sub.19 H.sub.20 N.sub.4 O.sub.3                                                     352.38                                                                             200                                                                               44 Calcu- lated (%) Found                                                             63.04 64.94                                                                        6.72 5.75                                                                         15.90 15.80          730693                                                                             CH.sub.3                                                                               ##STR39##         C.sub.20 H.sub.24 N.sub.4 O.sub.3                                                     368.42                                                                             134                                                                               62 Calcu- lated (%) Found                                                             65.20 65.15                                                                        6.57 6.78                                                                         15.21 15.25          __________________________________________________________________________

The compounds of formula I have been tested on animals in the laboratory and have been shown to possess antiulcerous, antibronchoconstrictive and anticholinergic, analgesic, antihistaminic, diuretic, cardiovascular analoptic, antiinflammatory and hypertensive properties.

1. ANTIULCEROUS PROPERTIES.

The compounds of formula I, administered by oral means, reduse the extent of gastric ulcers provoked in a rat by typing of the pylorus (Shay ulcers).

Thus, the compound of Code No. 72 498, administered in a dose of 50 mg/Kg/i.d., permits a reduction of 35% of the Shay ulcers in a rat.

2. ANTIBRONCHOCONSTRICTIVE AND ANTICHOLINERGIC PROPERTIES.

Injected by intraduodenal means, the compounds of formula I are capable of opposing the bronchoconstriction provoked in the guinea-pig by the intraveinous injection of acetylcholine and evaluated by the Konzett method.

By way of example, the administration of 100 mg/Kg/i.d. of the compound of Code No. 72 544, permits an inhibition of 50% of the bronchoconstriction provoked in the guinea-pig by the intraveinous injection of acetylcholine.

3. ANALGESIC PROPERTIES.

The compounds of formula I, administered to the mouse or rat by oral means, are capable of reducing the number of painful stretchings caused by the intraperitoneal injection of acetic acid or phenylbenzoquinone and they protect the rat against crying or jumping in the Randall and Selitto test.

BY WAY OF EXAMPLE:

- Table II lists the DE50 of different compounds according to the invention, and

- Table III indicates the results obtained by the administration of 100 mg/Kg/po of other compounds of formula I.

                  Table II                                                         ______________________________________                                                    Code No. of                                                         Nature of  compound              DE 50                                         test effected                                                                             tested       Animal   (mg/Kg/po)                                    ______________________________________                                         Test with  730 387      mouse    80                                            phenylbenzo-            rat      43                                            quinone                                                                                   730 372      mouse    20                                                                    rat      52                                                       730 367      mouse    72                                                                    rat      95                                            Randall &  730 387      rat      42                                            Selitto                                                                        test                                                                                      730 372      rat      40                                            ______________________________________                                    

                  Table III                                                        ______________________________________                                                                 Percentage diminution of                               Nature of test                                                                            Code No. of  number of painful                                      effected   compound tested                                                                             stretchings (%)                                        ______________________________________                                         Test with  730 693      70                                                     acetic acid                                                                                72 545      70                                                     Test with                                                                      phenylbenzo-                                                                              730 508      60                                                     quinone                                                                        ______________________________________                                    

4. ANTIHISTAMINIC PROPERTIES.

The compounds of formula I, introduced in the conserving medium, are capable of opposing the contractural action of histamine on the isolated ileon of the guinea-pig. This activity is evaluated taking promethazine as standard.

Thus, the compound of Code No. 72561 provides an antihistaminic activity equivalent to 1/15th that of promethazine.

5. DIURETIC PROPERTIES.

The compounds of formula I, administered by oral means to the mouse, simultaneously with a volume of 1 ml. of an isotonic solution of sodium chloride per 25g of the corporeal weight of the mouse, are capable of provoking an augmentation of the volume of urine emitted by reference to control animals, the volume being measured for 6 hours following administration.

Thus, the administration of 25 mg/Kg/po of the compounds of Code Nos. 730 508 and 730387 produced an augmentation of the urinary elimination by 70% and 55%, respectively.

6. CARDIOVASCULAR ANALEPTIC PROPERTIES.

These properties are shown by an augmentation of the force of contractions (positive inotrope action) in the isolated heart of the guinea-pig maintained in a conserving medium and under appropriate experimental conditions.

By way of example, the compounds of Code Nos. 730 387 and 730 372 respectively provoke an augmentation of 75% and of 50% in the force of contractions in a concentration of 0.5 μg/ml.

7. ANTIINFLAMMATORY PROPERTIES.

The compounds of formula I administered to the rat by oral means, provoke a diminution of the local oedema caused by the sub-plantar injection of carraghenine or Kaolin and oppose the inflammation caused by the Freund adjuvant. Administered by oral means to the guinea-pig, they reduce the erythema caused by ultra-violet irradiation.

The results are listed in the following table IV

    __________________________________________________________________________                                    Protection                                                                     against                                                                        arthritis                                                                      by Freund                                              Reduction of                                                                              Protection against                                                                          adjuvant                                               oedema with                                                                               erythema by  Dose                                                   carraghenine                                                                              ultra-violet administ-                                                                            Protect-                                  Code No.                                                                              or Kaolin  Dose         ered  ion                                       of compound                                                                           DE 50      administered                                                                          Protection                                                                           (mg/Kg/po)                                                                           (%)                                       tested (mg/Kg/po) (mg/Kg/po)                                                                            (%)                                                   __________________________________________________________________________     730 387                                                                               38 (carraghenine)                                                                         100    60    --    --                                               27 (carraghenine)                                                       730 372                        200   55                                                6 (Kaolin)                                                                               --     --                                                    730 367                                                                               47 (carraghenine)                                                                         100    50    --    --                                        __________________________________________________________________________

Also, the administration of the compound of Code No. 730 367 in a dose of 100 mg/Kg/po permits a diminution by 75% of the local oedema caused by the injection of Kaolin.

8. HYPERTENSIVE PROPERTIES.

Administered by intraveinous means, the compounds of formula I provoke an increase in the arterial pressure of an anaesthetised rat.

By way of example, the administration of the compound of Code No. 730 693 in a dose of 2 mg/Kg/i.v., provokes an increase in the arterial pressure of an anaesthetised rat by 25% for a period of the order of 30 minutes.

As a result of a comparison between the pharmacologically active doses mentioned above and the lethal doses listed in the following Table V, the difference between said doses is sufficiently great to permit the utilisation of the compounds of formula I in therapeutics.

    ______________________________________                                         Code No. of                                                                    compound   Dose administered                                                                             Percentage mortality                                 tested     (mg/Kg/po)     %                                                    ______________________________________                                          72 498    2000           0                                                     72 544    2000           0                                                     72 561    2000           0                                                     72 545    2000           0                                                    730 387    2000           0                                                    730 372    1500           ≃ 50                                   730 367    2000           0                                                    730 508    2000           0                                                    730 693    2000           ≃ 50                                   ______________________________________                                    

The compounds of formula I are useful in the treatment of gastro-duodenal ulcers, visceral spasms, asthma, diverse originating pains and painful inflammations, allergies, oedemas and hypotension.

They may be administered by oral means in the form of tablets, dragees and gelules, containing 50 to 500 mg. of active ingredient (1 to 6 times a day), by parenteral means in the form of injectable ampoules containing 10 to 250 mg of active ingredient (1 to 3 times a day) by rectal means in the form of suppositories containing 25 to 400 mg of active ingredient (1 to 3 times a day) and in the form of suspensions containing 0.5 to 5% of active ingredient (20 to 60 drops, 1 to 3 times a day).

Accordingly, the present invention also relates to a therapeutic composition comprising a compound of the general formula I, together with a therapeutically acceptable carrier. 

What we claim is:
 1. A compound having the formula ##STR40## in which R is alkyl having one to 4 carbon atoms, phenyl, or phenyl substituted by at least one halogen or by a trifluoromethyl, ##STR41## in which R₁ is hydrogen or alkyl containing one to 4 carbon atoms.
 2. A compound as claimed in claim 1, in which R is methyl and R₁ is hydrogen.
 3. A compound as claimed in claim 1 in which R is methyl and R₁ is methyl.
 4. A compound having the formula ##STR42## in which R is alkyl having one to 4 carbon atoms, phenyl, or phenyl substituted by at least one halogen or trifluoromethyl, ##STR43## in which R₁ is 2,3-dihydroxyprop-1-yl. 